Automatic compensating gtjn sight



Aug. 13, 1929. R. KAUCH ET AL I AUTOMATIC COMPENSAT ING GUN SIGHT Filed April 30, 1923 O INVENTOR ATTORNEY I Aug. 13, 1929. R. KAUCH ET AL 1,724,093

AUTOMATIC COMPENSATING GUN SIGHT Filed April 30, 1925 6 Sheets-Sheet 2 ATTRNEY Aug. 13, 1929. R. KAUCH ET AL 1,724,093

AUTOMATIC COMPENSATING GUN SIGHT Filed April :50, 1925 r 6 Sheets-Sheet 3 RM :ZVENTOR BY 5, lw

ATTORNEY Aug. 13, 1929. R. KAUCH ET AL AUTOMATIC COMPENSATING GUN SIGHT Filed April 50, 1925 6 Sheets-Sheet 4 IN VEN TOR QM L/ ATTORNEY 1929. R. KAUCH ET AL AUTOMATIC COMPENSATING GUN SIGHT Filed April 30, 1925 6 Sheets-Sheet 5 IN VEN TOR y v ATTORNEY Aug. 13, 1929. R. KAUCH ET AL AUTOMATIC COMPENSATING GUN SIGHT Filed April 50, 1923 6 Sheets-Sheet 6 fid y ATTORNEY Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

AUTOMATIC QOMPEN SATIN G GUN SIGHT.

Application filed April 30, 1923. Serial No. 635,756.

This invention relates to an automatic compensating gun sight the object in view being to provide means in connection with a gun and gun sight which will automatically compensate for the angular velocity between two airplanes, for example, or in other words give the necessary lead in order to hit an enemy airplane from an airplane flying at full speed with a projectile fired by a machine gun or cannon. The mechanism or apparatus will also compensate for the fall of the projectile in trajectory at various predetermined ranges. The range factor does not affect the accuracy of the correction for angular velocity within certain ranges. In other words the correction is made angularly and is not affected by ranges until the point is reached where the drift, due to windage, will be noticed.

In the accompanying drawings- Figure 1 is a side elevation of a flexibly mounted aircraft machine gun showing the compensating mechanism mounted thereon;

Figure 2 is a plan View of the same partly broken away in section for better illustration;

Figure 3 is an end elevation of thegun and sighting apparatus looking toward the muzzle of the gun;

Figure 4 is an enlarged vertical sectional View of the cross hair mechanism;

Figure 5 is also a sectional view thereot taken at a right angle to Figure 4;

Figure 6 is a diagram of the wiring sys- Figures 7, 8, 9 and 10 are chart diagrams illustrating the method of sighting on the enemy airplane .orother target;

Figure l ll's a ,view showing the cross hair shifting means;

.Fig'urelfZis an inverted viewtaken on the line 12,f12 of Fig. li showing a portion'of the hydraulic means @for controlling the electrical actuating means of the cross hair mechanism I Figure 13 isan ZeleVatiOn of the same taken at; a. right. ai igleto Figure 12 Figure plaids a se ction taken transversely and centrally of "Figure 12.

Ii 4 rd to facilitateithedescription and indenstanding, of. ,the. entire apparatus, the

- tained by using the other eye.

description will be subdivided into units, namely, the range finder, the cross hair shifting means and the control for cross hair shifting means.

Referring primarily to the range finding means, and in order to explain the action of this part of the apparatus, let us consider the case when the gunners vision is entering the opening 1 of the range finder 2, Figure 2. In this case the line of vision will be deflected and follow a path shown by the dashed and dotted line 3; that is his vision will first strike the double prism 4 mounted just within the eye-piece. At this point the vision will be separated into two parts, one part being reflected to the left and passing through the lens 5, thence to the prism 61 from which point it will follow a line parallel to the original line.of vision to the enemy airplane. The portion of the vision which is reflected to the right will be reflected by the prism f in such a way as to cause it to fall upon the target. This arrangement permits the exact range of the enemy airplane to be determined through the calibration of the angle between the lines of vision shown by the dashed and dotted lines of Figure 2. This arrangement will produce an inverted and an erect image of the enemy airplane as observed by the gunner when the range finder is not adjusted to suit the range as in Figure 7. Figure 8 shows the enemy airplane as it will appear to the gunner when the range finder is set to the exact range at which the airplane is flying. Considering the case where the gunners right eye is closed and he is observing only with his left eye, his vision will pass through the eye piece 8, hence, through lens 9, across at the focal point 10, pass through the second lens 11 from which it will follow the dashed and dotted line 12 to the enemy airplane. This arrangement permits a vision similar to the sight chart shown in Figure 9, in which case the enemy airplane will appear right side up and slightly larger than the vision ob- This is accomplished through the magnification obtained by the lens 9. It is the idea of the sight to use both eyes simultaneously so that the enemy airplane will appear as shown in.

the sight chart, Figure 10; that is the right eye will record a double image of the enemy airplane, one of which is inverted and the other erect, while the left eye will record an upright outstanding tar et.

Due to the fact that 1t is necessary to mtroduce a correction for thctrajectory of the bullet or projectile, the knob 13 which controls the angle of the angular prism 7 through the bevel gears 14 and 15 is connected by spur gears 16 and 17 to the shaft 18 (see Fig. 3') which actuates a worm wheel 19 by rotation of a worm 20. A movement of the worm wheel 19 rotates a threaded shaft 21 which in turn raises or lowers a shoe 22 resting on the frame f the gun. This arrangement causes mo tment of the knob 13 to effect an adjustment which will compensate for the fall of the projectile in trajectory.

The cross hair shifting means will now be described. It is the purpose of this mechanism to shift the cross hairs 23 and 24 mounted in the telescopic sight casing 25, an.

amount which will compensate for the angular velocity between the two airplanes 1n questlon. The mechanlsm is simple in construction, as shown in Figures 4 and 5, and

comprises in connection with and housed in the casing 25, fixed magnets 27 and 28 for the cross hair members, which magnets furnish a field current and influence levers 31 and 32 at the extremity of which are mounted cross hair needles 23 and 24. Part of the current flowing through the instrument is shunted through shunt coils 33 and 34 shown in the center of circular 'fixed magnets 27 This arrangement causes the lever which controls the cross hairs to move anainount from a central position directly proportional to. the amount of current flowingthrough the-circuit. It is to be understood, of course, that two arms 31 and 32,

with cross'hair members 23 and 24 and magnets-27 and 28 and coils 37 and 38 are used asp-indicated in the drawings. The means for controlling the-cross hair shifting means will nowibe described.

By reference to Figures 1 and 3 it will be noted that :We use two syl hons for each cross hair, those operating t e cross hair 23 being 40 and 41. The'se-sylphons are mounted in position on the gun mount 42 through. the use of a bracket 43 and are connected to- ','gether by a rack member at 44, which engages the teeth of an actuating pinion at 45,

having a fixed relation to the gun mount soas. to be turned when the gun is turned about its vertical axis, (see 44' and 45' Fig. 1.) This arrangement causes movement of the-gun in a horizontal plane to shift the rack 44,-in such a way as to displace the' shown in Figures 11, 12 and 13. The unit for shifting the cross-hair 24 is identical in structure for that used for shifting the crosshair 23 and is illustrated in the drawings wherever ossible with the same numerals primed. 8f course, it is to be understood that the cross hair 24 is to be shifted by motion of the 11 about a horizontal axis. The displace liquid is'carried through the tubes 46 and 47 to the unit ,5 sho'wn in Figures 11, 12, 13 and 14. y observing these figures it will be noted that the electric current control arm 48, is mounted in such a wayas to cause the position to change an amount which will depend upon the time rate of volume ofliquid displaced between the chambers 49 and 50; that is the arm 48 is geared permanently to a vane 51, which is mounted on the shaft 52, journalled in bearing 53. This vane is constructed in such a way as to maintain a liquid-tight joint regardless of the direction of its movement.-

This is accomplished by the use of the bear-' ing 53, having a ground fit along'the lines tion, as shown in Figure 12, separates the in terior of the casing 25, into chambers '49 and 50. Any movement of the liquid, no matter how minute, will cause a corresponding movement of the vane 51. This, together with the fact that the vane 51 is directly coupled to the electric control arm 48 causes the latter to shift an amount directly proportional to the speed of movement ofthe liquid. It will be observed that there are two complete units similar to the one above described. This arrangement is necessary owing to the fact that movement of the gun, either vertically or horizontally or in a direction, which is the component of the two, must be compensated for in firing. The description just completed was described particularly with reference to the shifting of the cross-hair 23. Wherever racticable the similar structure used for t e shifting of the cross-hair 24 has been indicated in the .drawin s, with the same numerals with the rent from the storage battery 60, will flow in the direction of the arrow 61, or from the positive to the negative side of the battery. The fundamental requirement of this partot the device is that the control arm -18, assmnes a neutral positionavhen there is no pivotal movement of the gun, and that the neutral position of this part of the device registers zero orassumes a central position upon the indicator needle 31. l\lovement of the control arm 48, in a clockwise direction, caused by a colmter-cloelnvise movement of the gun will cause a counter-clockwise movement of the needle arm 31. The cross-hairs visible in the sight are fastened to the needle 31 which condition causes the cross-hair to shiftan amount corresponding'to the movement of the needle 31. A counter-clockwise movement of the control arm 48 caused by a clockwise movement of the gun reverses the current and causes a clockwise movement of the needle 31 which action will enable a corresponding movement of the cross-hair mounted thereon. This may be more clearly understood by referring to Figure 6 in which the vane 51, is shown moving in the direction of the arrow 62, which will cause rotation of the large spur gear 63 in the direction of the arrow 64. This will cause a movement of small pinion 65 on shaft 86, in the direction shown by the arrow 66 and a movement of the control arm 48 in the direction shown in the arrow 67. This, through the action of the resistance coil 68, will cause a decrease in the amount of the electric current flowing through the lines 87 and 69, in a direction shown by the arrow and thence through the lead 88 to the battery. This will cause a movement of the needle 31, in the direction shown by the arrow 71, which direction, it

will be observed is identical with the direction of the arrows 62 and 64. In other words, the correction obtained must be in a direction so as to lead the enemy airplane. The instant that movement of the gun is stopped, the spring 56 will return the control arm 18 to a neutral position, in which position there is no electric current flowing through the device, but movement of the gun in the opposite direction will reverse the cycle of operation described above and through the action of the resistance unit 68 will cause the cross-hair 23 mounted on the needle 31 to be offset an amount directly proportional to the offset obtained on the control arm 48.

The above specific description has been made with reference to the movement of the cross-hair 23. The structure provided for movement of the cross-hair 24 is identical and has been indicated wherever practicable in the drawings by the same numerals with the addition of the prime.

The gun assembly is mounted on the usual scarf mount 80. A fluid reservoir 81, is connected in series with the sylphonsystems.

The vane actuating mechanisms are suitably encased in casings S5.

It is believed that the operation of the various parts of this device have been described in such detail that nofurther description of the device as a whole is necessary.

o claim:

1. In an automatic compensating gun sight, the combination of a gun mount and gun mounted thereon to permit both vertical and horizontal rotative movement of the gun, a gun sight mounted to move with the gun and embodying angularly related movable cross hair members, means for shifting said cross hair members embodying a hydraulic system set in action by rotati've movement of the gun, and electrical means controlled by the hydraulic means and acting directly to move the cross hair members.

2. In an automatic compensating gun sight, the combination of a gun mount and gun mounted thereon to permit both vertical and horizontal rotative movement of the gun, a gun sight mounted to move with the gun and embodying angularly related-movable cross hair members, means for shifting said cross hair members embodying a hydraulic system set in action by rotative movel ment ot the gun, and electro-magnet1d means controlled by the hydraulic means and acting directing to move the cross hair members, said shifting means being designed to move the cross hair members in such ratio to the gun movement as to cause the sighting line to lead a moving target by an amount' which will compensate for the speed of such target.

3. In an automatic compensating gun sight, the combination of a gun mount and gun mounted thereon to permit both vertical and horizontal rotative movement of the gun, a gun sight mounted to move with the gun and embodying movable cross hair members, and means embodying hydraulic means and electromagnetic means controlled thereby operating between the gun mount and gun sight to shift the cross hair members at such a speed in relation to the gun movement as to compensate for the speed of a moving target as the cross-hair members are maintained trained thereon.

4t. In an automatic compensating gun sight, the ecombination of a gun mount and gun mounted thereon to permit of a horizon tal rotative movement of the gun, a gun sight mounted to move with the gun and embodying movable cross hair members, and apparatus embodying hydraulic and electromagnetic units controlled by the gun movement operating to shift the cross hair members to correct for the speed of a moving target.

5. In an automatic compensating gun sight, the combination of a gun mount and a gun mounted thereon to permit both vertical Il'lGlIlbOlS to correct for the speed and range and hOI'lZODtiLl rotative movements of the of a mov ng target. gun, a gun slghb mounted to move wlth the In testimony whereof, We aifix our signa- 0 gun and embodying movable cross hair memtures.

hers, an apparatus embodying hydraulic and electromagnetic units controlled by the gun ROBERT KAUCH.

movements operating to shift the cross hair I CHARLES L. PAULUS. 

